use git check-ignore instead of git ls-files

lib/synvert/core/utils.rb

@@ -3,6 +3,7 @@
 require 'net/http'
 require 'uri'
 require 'open-uri'
+require 'open3'
 
 module Synvert::Core
   class Utils
@@ -35,13 +36,19 @@ def load_snippet(snippet_name)
       # @return [Array<String>] file paths
       def glob(file_patterns)
         Dir.chdir(Configuration.root_path) do
-          all_files = if Configuration.respect_gitignore
-            `git ls-files --cached --others --exclude-standard #{file_patterns.join(' ')}`.split("\n")
-          else
-            file_patterns.flat_map { |file_pattern| Dir.glob(file_pattern) }
+          all_files = file_patterns.flat_map { |pattern| Dir.glob(pattern) }
+          ignored_files = []
+
+          if Configuration.respect_gitignore
+            Open3.popen3('git check-ignore --stdin') do |stdin, stdout, stderr, wait_thr|
+              stdin.puts(all_files.join("\n"))
+              stdin.close
+
+              ignored_files = stdout.read.split("\n")
+            end
           end
 
-          filtered_files = filter_only_paths(all_files)
+          filtered_files = filter_only_paths(all_files - ignored_files)
 
           filtered_files -= get_explicitly_skipped_files
         end

spec/synvert/core/utils_spec.rb

@@ -78,14 +78,21 @@ module Synvert::Core
           Configuration.respect_gitignore = true
         end
 
-        it 'gets all files' do
-          expect(Object).to receive(:`).and_return(
-            [
-              'app/models/post.rb',
-              'app/controllers/posts_controller.rb'
-            ].join("\n")
+        it 'correctly filters out ignored files' do
+          file_patterns = ["**/*.rb"]
+          all_files = ["app/models/post.rb", "app/controllers/posts_controller.rb", "app/controllers/temp.tmp"]
+          not_ignored_files = ["app/models/post.rb", "app/controllers/posts_controller.rb"]
+          command_output = "app/controllers/temp.tmp\n"
+
+          allow(Open3).to receive(:popen3).with('git check-ignore --stdin').and_yield(
+            instance_double(IO, puts: nil, close: nil),
+            StringIO.new(command_output),
+            StringIO.new(''),
+            instance_double(Process::Waiter, value: instance_double(Process::Status, success?: true))
           )
-          expect(described_class.glob(['**/*.rb'])).to eq(['app/models/post.rb', 'app/controllers/posts_controller.rb'])
+          allow(Dir).to receive(:glob).and_return(all_files)
+
+          expect(described_class.glob(file_patterns)).to match_array(not_ignored_files)
         end
       end